voltage from ignition coil

Jan 05, 2007 13 Replies

Is it possible to "save" the voltage output from ignition coil on some high voltage capacitor bank? The output is between 10-15 KV.



So, basicly my question would be:



- How to save this i.c. high voltage output on capacitor bank and what design should i use.



I can connect 15... 1KV capacitors, but i dont think that just this, would do the trick...


You do understand this can kill you? You can store quite a large charge in the garden varierty disk capacitors but it will not be the whole 15kv. It can burn a hole in your hand tho. When you start ganging these things together you can get up into the "stick you hand in the TV" category.

You do understand this can kill you?

------------------------------------------------------------- Dont worry :-). Its good isolation and am taking big care in security part. Basicly i have two options. To convert this high voltage to higher current and then to pass it to capacitor bank or to pass it directly to capacitor bank.

****************************************************** Problem: If i use first approach i dont know how to use such high voltage on transformer.

Question: What is the "real / tested" current on such voltage.

If you plan on "saving" the charge you can, believe it or not, pick up some voltage from your TV screen.

If you "ground" your screen when the set if off (by placing your hand on the screen) and the turn the set on it will acquire a charge. You can draw that charge off with time foil with a conductive lead to your capacitor bank.

Repeated cycles of "off", "discharge", "on" will permit you to charge your capacitor bank to the fringes of 20 kV.

As far as an ignition coil (automobile type) is concerned, I don't think it has the "amps" to kill you.

First thing check your insurance policy as you apparently have no idea of what you are doing.

Suppose you can charge a 1 microfarad capacitor to 15KV (if you can find a

15KV 1 microfarad capacitor or equivalent) and have a HV diode to prevent discharge back through the coil between pulses - then you will have a bit less than 120 watt-seconds of energy stored, even if you run it all day. What's the point of all the effort for such little outcome?

Don't play with dangerous toys that you don't understand. It isn't worth it.

Don Kelly snipped-for-privacy@shawcross.ca remove the X to answer

added comment The ignition coil can hurt you, the capacitor discharge can kill you.

One of the methods used to charge capacitors efficiently for laser capacitor banks is to use the flyback principle (inductive kick) from interrupting inductive circuits. As others have mentioned, you need to use an isolating diode to prevent discharge between pulses.

Bill

-- Fermez le Bush

The main thing that i need is to find a way to "save" this HV for future use. I not making sparks or something like this.

Calculations: Im passing 200v DC ( from 50uF capacitor ) to ignition coil and you can see the spark on the spark gap. I dont know what is the voltage output of the i.c. but i guess it's around

10-15KV.

Goal, exp. and conclusion: Im trying to find some way to use/save this HV coil output so i can convert this high voltage to high current. Of course this is the tricky part becuse... i can not use ( as far as i know ) standard converters to produce high current, regarding to such HV. This is the part where i need your help.

So:

1.) Saving the HV from the coil 2.) converting to high current

I suspect that there is a natural reluctance, by many of the posters here, to give you any help towards you killing yourself or other(s). Quite frankly, if you don't have the knowledge how to generate and store extremely high voltages, you are very unlikely to have the knowledge on how to handle such voltages safely. A single mistake can easily be fatal. Even if not fatal, high voltage burns are very painful and can be very slow to heal. They can also require extensive and very expensive plastic surgery.

It might help if you define what you mean by "high current". eg, a single pulse with a 20nSec rise time, a duration of 1uSec, a 100nSec fall time and a peak value of 10kA. eg a constant current of 10kA for 10 seconds with rise and fall times less than 1mSec.

It might also help if you define what the load is going to be.

Dead right.

As a teenager, I played around with ignition coils, rectifiers and home-made HV (and rather high capacity) capacitors, and produced >2" really meaty sparks (until my capacitors died). But I'm extremely reluctant to go into details of how to do this if I'm not supervising the experiment, as it's well lethal if you screw up.

If it's the same person who was asking a few weeks ago, he doesn't seem to have taken any notice of the advice I did give him back then anyway.

On 06 Jan 2007 15:15:49 GMT Andrew Gabriel wrote: | In article , | =?UTF-8?B?UGFsaW5kcuKYu21l?= writes: |> I suspect that there is a natural reluctance, by many of the posters |> here, to give you any help towards you killing yourself or other(s). | | Dead right. | | As a teenager, I played around with ignition coils, rectifiers | and home-made HV (and rather high capacity) capacitors, and | produced >2" really meaty sparks (until my capacitors died). | But I'm extremely reluctant to go into details of how to do | this if I'm not supervising the experiment, as it's well | lethal if you screw up. | | If it's the same person who was asking a few weeks ago, he | doesn't seem to have taken any notice of the advice I did | give him back then anyway.

Back in the late 1960's I had one of those Heathkit experimenter boards, about the middle of the line. It operated on 4 C cell batteries for a

6 volt DC level. After getting board with some of the various circuits in the manual, I played around with a few of my own. Among them was a couple circuits to cause the relay to oscillate. One of them operated in the mode that closed the N.O. contact to short the coil, which in turn let the contact open again. The other put the coil in series with the N.C. contact. From this latter one I notice a spark coming from the contact. I played around with that one for a while until I happened to touch a couple contacts on the thing and go a nasty shock. That coil being opened was sure letting our quite a high voltage. I never did measure it, but it felt like more than 120 volts.

-

I will reinforce what others have told you. You are playing with things that can kill you, and are way over your head as far as your knowledge goes. Producing and storing high voltage requires specialized knowledge and safety procedures, which I am pretty sure you don't have any idea about. Please don't play with this further until you have received some formal training.

Ben Miller

- Benjamin D. Miller, PE B. MILLER ENGINEERING

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